開放經濟體系下之廢紙回收的最適環境政策

Optimal Environmental Policies for Waste Paper Recycling

由於國際間紙品與廢紙貿易頻繁、廢紙市場為不完全競爭結構、及紙品消費會產生環境污染與廢紙回收會帶來環境效益等特性，本文乃因應廢紙回收再生循環體系的運作，設計了一套理論模型來分析在開放經濟體系下的最適環境與貿易政策，俾能矯正市場失靈的現象。本文所考慮的政策性工具除了根據皮古稅(Pigouvian tax)的原則來課稅與補貼外，還兼顧關稅這項特殊的政策性工具；本文結果顯示：最適紙品消費的垃圾處理費應等於邊際污染成本，而廢紙回收再生的補貼率應等於邊際環境效益加上生產者的邊際利潤（此即兩階段的補貼方式），而紙品和廢紙的關稅則與傳統國際貿易理論中的最適關稅相似，唯一的不同在於最適關稅將與本文所求出之最適環境政策組合息息相關。

Several policy instruments are taken into account to formulate a general equilibrium model to address the optimal environmental policies for waste paper recycling. In a hierarchical oligopsonic waste paper market, the sum of the subsidies to the supplier and the demander of waste papers should be greater than the marginal environmental benefit from waste paper recycling, unless both groups are purely competitive agents. With budget surplus, the optimal tariffs on imported waste papers and paper commodities are conformable with those derived from the classical trade theories. The only difference is that such tariffs will be no longer independent of the prevailing environmental policies. Furthermore, it is shown that who should be subsidized more is not a relevant issue from the perspectives of efficiency. It could be made based on other criteria, and may not cause distortion in efficiency as long as the required conditions not violated.